Flash-board holder for dams.



PATENTBD SEPT. 19, 1905.

W. L. CHURCH.

FLASHBOARD HOLDER FOR DAMS.

APPLICATION FILED JUNE 2,1905.

PATENT QFEIGE.

WILLIAM L. CHURCH, OF NEWTON, MASSACHUSETTS.

FLASH-BIOARVD HOLDER FoR DAMS.

Specification of Letters Patent.

fiatented. Sept. 19, 1905.

Application filed June 2, 1905. Serial No. 263,447.

To (LIZ wlwm, it may concern.-

Be it known that I, WILLIAML. CHURCH, of Newton, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Flash Board Holders for Dams, of which the following is a specification.

This invention has for its object to provide means for securely supporting on the crest of a dam a series of flash-boards for raising the height of water in the pond, the invention being intended particularly to permit a wall of flash-boards to be built of any desired height and also to permit the flash-boards to be readily released, so that they will be carried downstream by the escaping water whenever it is desired to lower the surface of the pond.

The invention consists in the improvements which I will now proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification, Figure 1 represents a transverse section of a dam embodying my invention. Fig. 2 represents a perspective sectional view showing a portion of the crest of the dam.

The same reference characters indicate the same parts in both figures.

In the drawings, (4 represents the crest of a dam, which is here shown as composed of concrete, the dam being of hollow or shell form and having a cavity or chamber (0 below the crest.

Z) represents a guide which extends vertically through the crest of the dam and is in this case formed by inserting a metal tube or bushing in the concrete.

0 represents a stout metal post which is movable lengthwise in the guide I) and is adapted to be projected above the crest of the dam to support the flash-boards d. The post 0 is preferably provided at its upper end with a laterally-projecting lug or ear 0, adapted to engage the upper edge of the top flash-board. It will of course be understood that the posts 0 are at the downstream side of the flash-boards, so that the latter are held against the post by the pressure of the water in the pond, the lugs 0 preventing vertical displacement of the flash-boards. In securing the flash-boards in place it is only necessary to raise the posts 0 to the desired height, an operation which may be efiiected either from above or underneath the crest of the dam, and place the flash-boards against the posts, as indicated in the drawings. When it is desirable to liberate the iiash-boards and release the water confined thereby, this operation may be performed by giving a half-rotation to each of the posts 0, thus removing the lugs 0 from engagement with the flash-boards, and then retracting the posts until the lugs 0 enter recesses or sockets a formed for their reception in the crest of the dam. The flash-boards are thus released and carried over the dam by the escaping water.

It will be seen that the chamber or cavity a under the crest of the dam enables the posts 0 to be manipulated from below the crest. In the present embodiment of my invention the chamber a is provided with a foot-bridge e,

which extends along the dam under the crest and enables access to be conveniently had to all the posts of the series. Suitable means for manipulating or operating the posts are provided, such as handles 0 affixed to the lower ends of the posts. If desired, stuffingboxes 9 may be provided at the lower portions of the guides b to prevent leakage around the posts.

It will be seen that the posts vertically movable in the guides in the crest of the dam are adapted to be retracted and held with their upper ends below or flush with the crest of the dam when not in use, so that they will be free from liability to injury from floatinglogs, ice, &c., and that whenever the flash-boards are required the posts are readily adjusted to their operative positions.

I claim- 1. A dam having at its crest a series of guides, and flash-board-supporting posts movable in said guides.

2. A dam' having at its crest a series of guides, and posts movable endwise and rotatable in said guides, and provided with ears or lugs adapted to engage the upper edges of flash-boards.

3. A dam. having in its crest a series of guides, and pockets communicating with the upper ends of the guides, and posts movable in said guides and provided with flash-boardengaging ears or lugs adapted to occupy said pockets when the posts are retracted.

L. A darn having a chamber or cavity below its crown, guides extending from said chamber through thecrown, and flash-board-supporting posts movable in said guides and provided with operating means located in the chamber.

5. A dam having a chamber or cavity below its crown, guides extending from said chamber through. the crown, and flash-board-supporting posts movable in said guides and pro-' ing posts movable in said guides and extendvided with operating-handles at their lower ends within the chamber.

6. A concrete dam structure hollow below 5 its crown, tubular metal guides extending through the crown, and flash-board-supporting posts movable in said guides.

7. A dam having a chamber or cavity below its crown, guides extending from said cham- IO ber through the crown, flash-board-supporting into the chamber, and stuifing-boxes surrounding said posts.

In testimony whereof I have affixed my signature in presence of two Witnesses.

WILLIAM L. CHURCH.

Witnesses:

P. W. PEZZETTI, (J. F. BROWN. 

